CIELAB Color Space as a Field for Tracking Color-Changing Chemical Reactions of Polymeric pH Indicators.

Two types of cross-linked polymeric dye films that exhibit reversible color changes in response to pH were prepared. Upon protonation, films with a nitrophenol dye moiety (NP) changed from yellow to colorless, whereas films with an azobenzene dye moiety (AB) changed from yellow to reddish-purple. The colored light transmitted through these films from a D65 white-light source was measured colorimetrically, and the transition of the chromaticity point in CIELAB upon protonation of the polymeric dyes was observed. At low dye concentrations ([NP] < 4.7 × 10-5 and [AB] < 2.7 × 10-5 mol L-1), linear loci of the chromaticity points were displayed for both polymeric dye films, indicating perceptual linearity. This linearity is caused by the avoidance of nonlinear perceptual phenomena such as the Abney effect and the Bezold-Brücke phenomenon. The perceptual linearity of space is a necessary condition for achieving stoichiometric linearity, which requires an additional linear relationship between the dye concentration and each component, a*, b*, and L*. A geometric equation that included the AB concentration and the protonation ratio of AB was used to successfully depict, on the basis of stoichiometric linearity, the protonation of the polymeric AB films three-dimensionally in the restricted area of CIELAB.

Impact of acute coronary syndrome on early in-stent neoatherosclerosis as shown by optical coherence tomography.

Background: Patients with acute coronary syndrome (ACS) have a higher risk of requiring target vessel revascularisation after percutaneous coronary intervention (PCI) than patients with stable angina. Neoatherosclerosis is a significant risk factor for very late stent thrombosis, and the presence of neoatherosclerosis is independently associated with major adverse cardiac events. Aims: In this study, we used optical coherence tomography (OCT) to investigate the impact of ACS on neoatherosclerosis within 1 year after PCI. Methods: We investigated 102 patients (122 lesions) who had undergone PCI using a second-generation drug-eluting stent (DES) from March 2017 to November 2020 and were followed up with OCT within 1 year. The patients were categorised into the ACS group or non-ACS group according to their clinical findings at the time of target lesion treatment. We used OCT to investigate the presence of neoatherosclerosis. Results: The ACS group comprised 23 (22.5%) patients. There were no differences in the patients' clinical characteristics between the groups. The total stent length tended to be shorter in the ACS group than in the non-ACS group (24 mm vs 32 mm, respectively; p=0.09), but this difference was not statistically significant. The median duration from PCI was 290 days. Neoatherosclerosis was more frequent in ACS lesions (39% vs 4%; p<0.01), and implantation of a DES in ACS lesions was an independent predictor of neoatherosclerosis occurrence (odds ratio 9.70; p<0.01). Conclusions: This observational study using OCT indicates that stenting for ACS lesions is associated with early in-stent neoatherosclerosis.

Integrating surgical intervention and watch-and-wait approach in dMMR metastatic rectal cancer with pembrolizumab: a case report.

BACKGROUND: Treating rectal cancer presents challenges due to postoperative complications and reduced quality of life (QOL). Recent evidence supports the watch-and-wait (WW) approach for patients with a clinical complete response (cCR) following preoperative treatment. In this report, we discuss a case of metastatic rectal cancer with deficient mismatch repair (dMMR) treated successfully with pembrolizumab. CASE PRESENTATION: A 47-year-old male with dMMR rectal cancer and a single liver metastasis underwent treatment with pembrolizumab as neoadjuvant therapy. After 10 courses, the rectal lesion achieved cCR, prompting the selection of the WW approach. The liver metastasis showed significant shrinkage; however, the presence of a residual tumor was suspected, leading to a metastasectomy. A pathological complete response (pCR) was confirmed via histological examination. During a 24-month follow-up, there was no evidence of tumor regrowth, local recurrence, or distant metastasis. CONCLUSIONS: The WW strategy is increasingly accepted for patients achieving cCR after preoperative treatment. While pCR in dMMR rectal cancer patients treated with immune checkpoint inhibitors (ICIs) has been documented, accurately predicting pCR from imaging remains challenging. This case illustrates that integrating ICI therapy, surgical interventions, and the WW approach can effectively achieve both oncological safety and improved QOL in the treatment of dMMR metastatic rectal cancer.

Cytoreductive surgery without intra-peritoneal chemotherapy for metachronous colorectal peritoneal metastases.

BACKGROUND: Cytoreductive surgery and chemotherapy reportedly improve the prognosis of patients with metachronous peritoneal metastases. However, the types of peritoneal metastases indicated for cytoreductive surgery remains unclear. Therefore, we aimed to clarify the category of cases for which cytoreductive surgery would be effective and report the prognosis associated with cytoreductive surgery for metachronous peritoneal metastases. METHODS: This study included 52 consecutive patients who underwent cytoreductive surgery for metachronous peritoneal metastases caused by colorectal cancer between January 2005 and December 2018 and fulfilled the selection criteria. The median follow-up period was 54.9 months. Relapse-free survival was calculated as the time from cytoreductive surgery of metachronous peritoneal metastases to recurrence. Overall survival was defined as the time from cytoreductive surgery of metachronous peritoneal metastases to death or the end of the follow-up period. RESULTS: The 5-year relapse-free survival rate was 30.0% and the 5-year overall survival rate was 72.3%. None of the patients underwent hyperthermic intraperitoneal chemotherapy. The analysis indicated no potential risk factors for 5-year relapse-free survival. However, for 5-year overall survival, the multivariate analysis revealed that time to diagnosis of metachronous peritoneal metastases of < 2 years after primary surgery (hazard ratio = 4.1, 95% confidence interval = 2.0-8.6, p = 0.0002) and number of metachronous peritoneal metastases ≥ 3 (hazard ratio = 9.8, 95% confidence interval = 2.3-42.3, p = 0.002) as independent factors associated with a poor prognosis. CONCLUSIONS: Long intervals of more than 2 years after primary surgery and 2 or less metachronous peritoneal metastases were good selection criteria for cytoreductive surgery for metachronous peritoneal metastases from colorectal cancer.

Successful revascularization of coronary occlusion due to lotus root-like plaques by IVUS-based real-time three-dimensional wiring using the tip detection method in a patient with cardiac arrest.

A 32-year-old man, who was treated for T-cell lymphoma, presented in cardiac arrest. He had been treated for heart failure with reduced ejection fraction. Veno-arterial extracorporeal membrane oxygenation was initiated immediately. We diagnosed him as non-ST elevated myocardial infarction. Coronary angiography demonstrated the occlusion of the trifurcation in the proximal left anterior descending artery (LAD). We failed to advance the first guidewire into the distal LAD by angio-based conventional wiring. Intravascular ultrasonography (IVUS) of the proximal diagonal branch revealed two diaphragms separating the distal lumen without connection, which looks like lotus root-like appearance. We quickly penetrated the plaque using IVUS-based real-time 3D wiring using the tip detection method. The contrast injection via the microcatheter showed the distal diagonal branch (D2). After the balloon dilation in D2, IVUS image revealed a torn plaque between D2 and the distal LAD. Subsequently we advanced the guidewire to the distal LAD using IVUS-based real-time 3D wiring using the tip detection method through the tear of the plaque. Finally, we successfully performed the revascularization of LAD in a preferable procedure time. The patient recovered well and was discharged 39 days after cardiac arrest. This case highlights the efficacy of IVUS-based real-time 3D wiring using the tip detection method even in the emergent and challenging situation.

Long-term Outcome After Surgical Resection of Paraaortic Lymph Node Metastasis of Colorectal Cancer: A Multicenter Retrospective Study.

BACKGROUND: The significance of resection of paraaortic lymph node metastasis in colorectal cancer is controversial. OBJECTIVE: To clarify the prognosis of colorectal cancer after paraaortic lymph node metastasis resection. DESIGN: Multicenter retrospective study. SETTINGS: Thirty-six institutions in Japan participated in this study. PATIENTS: Patients with resected and pathologically proven paraaortic lymph node metastasis of CRC between 2010 and 2015. DATA SOURCES: Database and medical records at each institution. MAIN OUTCOME MEASURES: Overall survival after paraaortic lymph node metastasis resection, recurrence-free survival, and recurrence patterns after R0 resection of paraaortic lymph node metastasis. RESULTS: A total of 133 patients were included in the primary analysis population in this study. The 5-year overall survival rate (95% confidence interval [CI]) was 41.0% (32.0, 49.8), and the median survival (95% CI) was 4.1 (3.4, 4.7) years. Independent prognostic factors for overall survival were the pathological T stage (pT4 vs. pT1- 3, adjusted hazard ratio [aHR]: 1.91, p = 0.006), other organ metastasis (present vs. absent, aHR: 1.98, p = 0.005), time to metastases (synchronous vs. metachronous, aHR: 2.02, p = 0.02), and number of paraaortic lymph node metastasis (≥3 vs. <3, aHR: 2.13, p = 0.001). The 5-year recurrence-free survival rate (95% CI) was 21.1% (13.5, 29.7), with a median (95% CI) of 1.2 (0.9, 1.4) years. The primary tumor location (left- vs. right-sided colon, aHR: 4.77, p = 0.01; rectum vs. right-sided colon, aHR: 5.27, p = 0.006), other organ metastasis (present vs. absent, aHR: 1.90, p = 0.03), number of paraaortic lymph node metastasis (≥3 vs. <3, aHR: 2.20, p = 0.001), and hospital volume (<10 vs. ≥10, aHR: 2.18, p = 0.02) were identified as independent prognostic factors for recurrence-free survival. Paraaortic lymph node recurrence was the most common at 33.3%. LIMITATIONS: Selection bias cannot be ruled out because of the retrospective nature of the study. CONCLUSIONS: Less than three paraaortic lymph node metastasis was a favorable prognostic factor for both overall survival and recurrence-free survival. However, paraaortic lymph node metastases were considered to be a systemic disease and the significance of resection was limited. See Video Abstract.

Short- and long-term outcomes of surgical treatment for inguinal lymph node metastasis in rectal and anal canal adenocarcinoma.

AIM: The significance of lymphadenectomy and its indications in patients with inguinal lymph node metastasis (ILNM) of anorectal adenocarcinoma is unclear. This study aimed to clarify the surgical outcomes and prognostic factors of inguinal lymphadenectomy for ILNM. METHOD: This study included patients who underwent surgical resection for ILNM of rectal or anal canal adenocarcinoma with pathologically positive metastases between 1997 and 2011 at 20 participating centres in the Study Group for Inguinal Lymph Node Metastasis from Colorectal Cancer organized by the Japanese Society for Cancer of the Colon and Rectum. Clinicopathological characteristics and short- and long-term postoperative outcomes were retrospectively analysed. RESULTS: In total, 107 patients were included. The primary tumour was in the rectum in 57 patients (53.3%) and in the anal canal in 50 (46.7%). The median number of ILNMs was 2.34. Postoperative complications of Clavien-Dindo Grade III or higher were observed in five patients. The 5-year overall survival rate was 38.8%. Multivariate analysis identified undifferentiated histological type (P < 0.001), pathological venous invasion (P = 0.01) and pathological primary tumour depth T0-2 (P = 0.01) as independent prognostic factors for poor overall survival. CONCLUSION: The 5-year overall survival after inguinal lymph node dissection was acceptable, and it warrants consideration in more patients. Further larger-scale studies are needed in order to clarify the surgical indications.

Erdheim-Chester Disease with Pancreatic Enlargement Observed Using Contrast-enhanced Endoscopic Ultrasonography.

We herein report an unusual case of Erdheim-Chester disease (ECD), a rare non-Langerhans cell histiocytosis, and emphasize its unique presentation and diagnostic challenges. Our patient exhibited uncommon symptoms and significant organ involvement, particularly pancreatic enlargement that is not typically associated with ECD. Contrast-enhanced harmonic endoscopic ultrasonography (CEH-EUS) and EUS-fine needle aspiration (EUS-FNA) play crucial roles in the comprehensive assessment of the disease, demonstrating their superiority in identifying and characterizing elusive ECD lesions. This is the first report to document pancreatic lesions in patients with ECD evaluated using CEH-EUS. EUS-FNA is valuable for diagnosing rare diseases, including ECD, with diffuse pancreatic enlargement.

Impact of resection for ovarian metastases from colorectal cancer and clinicopathologic analysis: A multicenter retrospective study in Japan.

Aim: The aim of this study was to clarify the significance of resection of ovarian metastases from colorectal cancer and to identify the clinicopathologic characteristics. Methods: In this multicenter retrospective study, we evaluated data on ovarian metastases from colorectal cancer obtained from patients at 20 centers in Japan between 2000 and 2014. We examined the impact of resection on the prognosis of patients with ovarian metastases and examined prognostic factors. Results: The study included 296 patients with ovarian metastasis. The 3-y overall survival rate was 68.6% for solitary ovarian metastases. In all cases of this cohort, the 3-y overall survival rates after curative resection, noncurative resection, and nonresection were 65.9%, 31.8%, and 6.1%, respectively (curative resection vs noncurative resection [P < 0.01] and noncurative resection vs nonresection [P < 0.01]). In the multivariate analysis of prognostic factors, tumor size of ovarian metastasis (P < 0.01), bilateral ovarian metastasis (P = 0.01), peritoneal metastasis (P < 0.01), pulmonary metastasis (P = 0.04), liver metastasis (P < 0.01), and remnant of ovarian metastasis (P < 0.01) were statistically significantly different. Conclusion: The prognosis after curative resection for solitary ovarian metastases was shown to be relatively favorable as Stage IV colorectal cancer. Resection of ovarian metastases, not only curative resection but also noncurative resection, confers a survival benefit. Prognostic factors were large ovarian metastases, bilateral ovarian metastases, the presence of extraovarian metastases, and remnant ovarian metastases.

Incidence and risk factors of bowel dysfunction after minimally invasive rectal cancer surgery and discrepancies between the Wexner score and the low anterior resection syndrome (LARS) score.

PURPOSE: Bowel dysfunction after sphincter-preserving-surgery (SPS) impacts quality of life. The Wexner score (WS) and the low anterior resection syndrome (LARS) score (LS) are instruments for assessing postoperative bowel dysfunction. We analyzed the incidence of and risk factors for each symptom and examined the discrepancies between the two scores. METHODS: A total of 142 patients with rectal cancer, who underwent minimally invasive SPS between May, 2018 and July, 2019, were included. A questionnaire survey using the two scores was given to the patients 2 years after SPS. RESULTS: Tumor location and preoperative radiotherapy were independent risk factors for major LARS. Intersphincteric resection with a hand-sewn anastomosis (HSA) was an independent risk factor for high WS. Among the patients who underwent HSA, 82% experienced incontinence for liquid stools, needed to wear pads, and suffered lifestyle alterations. Of the 35 patients with minor LARS, only 1 had a high WS, and 80.0% reported no lifestyle alterations. Among the 75 patients with major LARS, 58.7% had a low WS and 21.3% reported no lifestyle alterations. CONCLUSION: The results of this study provide practical data to help patients understand potential bowel dysfunction after SPS. The discrepancies between the WS and LS were clarified, and further efforts are required to utilize these scores in clinical practice.

Prognostic factors of para-aortic lymph node metastasis from colorectal cancer in highly selected patients undergoing para-aortic lymph node dissection.

PURPOSE: We investigated the surgical outcomes of para-aortic lymph node (PALN) dissection in patients with colorectal cancer and assessed the prognostic factors related to the survival. METHODS: This single-center retrospective study included 31 patients with synchronous or metachronous PALN metastasis from colorectal cancer who underwent PALN dissection between January 2006 and December 2018. RESULTS: Twenty-one patients had synchronous PALN metastasis, and 10 had metachronous PALN metastasis. Seven patients had either simultaneous distant metastasis or a history of distant metastasis other than PALN metastasis at the time of PALN dissection. Eighteen patients underwent adjuvant chemotherapy. The 5-year overall and recurrence-free survival rates were 54.2 and 17.2%, respectively. A multivariable analysis revealed that rectal cancer, metachronous PALN metastasis, and three or more pathological PALN metastases were significantly poor prognostic factors for the recurrence-free survival. Among patients with rectal cancer, lower rectal cancer and lateral pelvic lymph node metastasis were poor prognostic factors for the overall survival. CONCLUSION: Curative PALN dissection for PALN metastasis from colorectal cancer is feasible with favorable long-term outcomes. A multidisciplinary approach, including surgery and chemotherapy, is needed for colorectal cancer with PALN metastasis to improve the long-term outcomes.

Tissue responses to everolimus-eluting stents implanted in severely calcified lesions following atherectomy.

Histopathological examination has revealed that stents on severely calcified plaques were associated with delayed vascular healing. Although atherectomy devices can increase the number of malapposed struts, tissue responses to implanted drug eluting stents in atherectomy patients remain largely unknown. This retrospective observational study included 30 patients who underwent atherectomy and everolimus-eluting stent (EES) deployment for severely calcified coronary lesions (biodegradable polymer EES (BP-EES), n = 15; durable polymer EES (DP-EES), n = 15). Optical coherence tomography was carried out at baseline and follow-up, and struts with acute stent malapposition (ASM) were categorized as struts on modified calcium (mod-Ca), non-modified calcium (non-mod-Ca), or non-calcium (non-Ca). Adequate vascular healing, defined as ASM resolution with neointimal coverage, was compared between the BP-EES and DP-EES groups. Multivariate linear regression analysis using a generalized estimated equation revealed that BP-EES use was associated with significantly better adequate vascular healing compared with DP-EES (odds ratio [OR]: 3.691, 95% confidence interval [CI] 1.175-11.592, P = 0.025). adequate vascular healing was associated with the underlying plaque morphology (mod-Ca vs non-mod-Ca: OR 2.833, 95% CI 1.491-5.384, P = 0.001; non-Ca vs non-mod-Ca: OR 1.248, 95% CI 0.440-3.543, P = 0.677). This study demonstrates that drug-eluting stent selection and calcium modification are possible factors affecting vascular healing of malapposed struts in severely calcified lesions.

The impact of staple transection of the dorsal venous complex and urethra on intraoperative blood loss in cooperative laparoscopic and transperineal endoscopic pelvic exenteration.

PURPOSE: While laparoscopic pelvic exenteration reduces intraoperative blood loss, dorsal venous complex bleeding during this procedure causes issues. We previously introduced a method to transect the dorsal venous complex and urethra using a linear stapler during cooperative laparoscopic and transperineal endoscopic (two-team) pelvic exenteration. The present study assessed its effectiveness in reducing intraoperative blood loss by comparing it with conventional laparoscopic pelvic exenteration. METHODS: This retrospective cohort study was conducted at a Japanese tertiary referral center. Eleven cases of two-team laparoscopic pelvic exenteration with staple transection of the dorsal venous complex (T-PE group) were compared to 25 cases of conventional laparoscopic pelvic exenteration (C-PE group). The primary outcome measure was intraoperative blood loss. RESULTS: There were no significant between-group differences in patient background. The mean intraoperative blood loss was significantly lower in the T-PE group than in the C-PE group (200 vs. 850 mL, p = 0.01). The respective mean operation time, postoperative complication rate, and R0 resection rate were similar between the T-PE and C-PE groups (636 min vs. 688 min, p = 0.36; 36% vs. 44%, p = 0.65; 100% vs. 100%, p = 1.00). CONCLUSIONS: Two-team laparoscopic pelvic exenteration with staple transection of the dorsal venous complex reduced intraoperative blood loss from the dorsal venous complex in a technically safe and oncologically feasible manner.

Clinical utility of the carcinoembryonic antigen level in patients with stage III colon cancer after surgery and adjuvant chemotherapy.

PURPOSE: The association between perioperative and post-adjuvant carcinoembryonic antigen (CEA) levels and recurrence and prognosis remains unclear. We aimed to evaluate whether perioperative CEA levels are an integral component of the assessment of recurrence and prognosis of patients with stage III colon cancer (CC). METHODS: This retrospective study was conducted at the Cancer Institute Hospital of the Japanese Foundation for Cancer Research from 2005 to 2013. We enrolled patients with stage III CC who underwent complete resection of a primary tumor and received adjuvant chemotherapy. We analyzed the association between perioperative and post-adjuvant CEA levels and recurrence-free survival (RFS) and overall survival (OS). RESULTS: A total of 564 consecutive patients were included in the analysis. The RFS and OS of patients with high postoperative CEA levels were significantly worse than those of patients with normal postoperative CEA levels. In the multivariate analysis, high postoperative CEA levels were associated with shorter RFS and OS. The number of risk factors, postoperative CEA levels, and T/N-stage all had a cumulative effect on RFS and OS. CONCLUSIONS: High postoperative CEA levels and the number of risk factors are associated with recurrence and worse prognosis for patients with stage III CC.

Quantification of pulmonary perfusion using LSIM-CT correlates with pulmonary hemodynamics in patients with CTEPD.

Background: Lung subtraction iodine mapping (LSIM)-CT is a clinically useful technique that can visualize pulmonary mal-perfusion in patients with chronic thromboembolic pulmonary disease (CTEPD). However, little is known about the associations of LSIM images with hemodynamic parameters of patients with CTEPD. This study investigates a parameter of LSIM images associated with mean pulmonary arterial pressure (mPAP) and validates the association between pulmonary vascular resistance, right atrial pressure, cardiac index, and exercise capacity in patients with CTEPD. Methods: This single-center, prospective, observational study involved 30 patients diagnosed with CTEPD using lung perfusion scintigraphy. To examine the correlation of decreased pulmonary perfusion area (DPA) with mPAP, areas with 0-10, 0-15, 0-20, and 0-30 HU in lung subtraction images were adopted in statistical analysis. The DPA to total lung volume ratio (DPA ratio, %) was calculated as the ratio of each DPA volume to the total lung volume. To assess the correlation between DPA ratios of 0-10, 0-15, 0-20, and 0-30 HU and mPAP, Spearman's rank correlation coefficient was used. Results: The DPA ratio of 0-10 HU had the most preferable correlation with mPAP than DPA ratios of 0-15, 0-20, and 0-30 HU (ρ = 0.440, P = 0.015). The DPA ratio of 0-10 HU significantly correlates with pulmonary vascular resistance (ρ = 0.445, P = 0.015). The receiver operating characteristic curve analysis indicated that the best cutoff value of the DPA ratio of 0-10 HU for the prediction of an mPAP of ≥30 mmHg was 8.5% (AUC, 0.773; 95% CI, 0.572-0.974; sensitivity, 83.3%; specificity, 75.0%). Multivariate linear regression analysis, which was adjusted for the main pulmonary arterial to ascending aortic diameter ratio and right ventricular to left ventricular diameter ratio, indicated that the DPA ratio of 0-10 HU was independently and significantly associated with mPAP (B = 89.7; 95% CI, 46.3-133.1, P < 0.001). Conclusion: The DPA ratio calculated using LSIM-CT is possibly useful for estimating the hemodynamic status in patients with CTEPD.

Endoscopic Surgical Skill Qualification System: propensity-score matched cohort analysis of accredited supervisors in laparoscopic rectal cancer surgery.

BACKGROUND: The Endoscopic Surgical Skill Qualification System (ESSQS) in Japan evaluates the surgical skills required for laparoscopic surgery as an operator as well as a supervisor. This study aimed to demonstrate the benefits of an ESSQS-certified surgeon's participation in laparoscopic rectal resections as a supervisor (assistant or advisor). METHODS: We retrospectively reviewed laparoscopic resection results for cStage II and III rectal cancer performed at 56 Japanese hospitals between 2014 and 2016. We used propensity score matching to generate paired cohorts with or without an ESSQS-certified supervisor at a one-to-one ratio. The impact of ESSQS-certified supervisors' participation on short-term outcomes was assessed. In the matched cohort, multivariable logistic regression analysis and multivariable regression analysis of postoperative complication rate and intraoperative blood loss were performed to further mitigate the impact of pathological factors. RESULTS: Two groups (n = 399 each) with or without an ESSQS-certified supervisor were well matched by clinical factors. The group with an ESSQS-certified supervisor had lower blood loss (68 mL vs. 98 mL, P = 0.036) and a lower incidence of severe morbidities of Clavien-Dindo grade ≥IIIa (8.0% vs. 13.3%, P = 0.016). Multivariable logistic regression analysis and multivariable regression analysis confirmed that the attendance of ESSQS-certified supervisors reduced postoperative complication occurrence (adjusted odds ratio: 2.28, 95% confidence interval: 1.38 - 3.80, P = 0.001) and intraoperative blood loss (estimated difference: -15.7 mL, P = 0.016). CONCLUSION: This study demonstrated the educational benefits of ESSQS-certified supervisors, including assistants and advisors, evidenced by their superior short-term outcomes.

InGaN/GaN superlattice underlayer for fabricating of red nanocolumnµ-LEDs with (10-11) plane InGaN/AlGaN MQWs.

In this study, the growth behavior of Indium gallium nitride (InGaN)-based nanocolumn arrays was investigated, and red emission nanocolumn micro-light emitting diodes (µ-LEDs) were fabricated. The internal structure of the InGaN/GaN superlattice (SL) layer under the multiple-quantum-well (MQW) active layers was evaluated using scanning transmission electron microscopy (STEM) analysis. It was revealed that the InGaN crystal plane at the top of the nanocolumn changed from the c-plane, (1-102) plane, to the (10-11) plane as the number of SL pairs increased. A semipolar (10-11) plane was completely formed on top of the nanocolumn by growing InGaN/GaN SLs over 15-20 pairs, where the InGaN/GaN SL layers were uniformly piled up, maintaining the (10-11) plane. Therefore, when InGaN/AlGaN MQWs were grown on the (10-11) plane InGaN/GaN SL layer, the growth of the (10-11) plane semipolar InGaN active layers was observed in the high-angle annular dark field (HAADF)-STEM image. Moreover, the acute nanocolumn top of the (10-11) plane of the InGaN/GaN SL underlayer did not contribute to the formation of the c-plane InGaN core region. Red nanocolumnµ-LEDs with anφ12µm emission window were fabricated using the (10-11) plane MQWs to obtain the external quantum efficiency of 1.01% at 51 A cm-2. The process of nanocolumnµ-LEDs suitable for the smaller emission windows was provided, where the flat p-GaN contact layer contributed to forming a fine emission window ofφ5µm.

Intratumoral Budding and CD8-Positive T-cell Density in Pretreatment Biopsies as a Predictor of Response to Neoadjuvant Chemoradiotherapy in Advanced Rectal Cancer.

BACKGROUND: Neoadjuvant chemoradiotherapy (CRT) is the standard treatment for advanced rectal cancer. Yet, the response to CRT varies from complete response to zero tumor regression. MATERIALS AND METHODS: The impact of intratumoral budding (ITB) and intratumoral CD8+ cell density on response to CRT and survival were evaluated in biopsy samples from 266 patients with advanced rectal cancer who were treated with long-course neoadjuvant CRT. The expression of epithelial-mesenchymal transition (EMT) markers was compared between patients with high and low ITB, using data from 174 patients with RNA sequencing. RESULTS: High ITB was observed in 62 patients (23.3%). There was no association between ITB and CD8+ cell density. The multivariable logistic regression analysis showed that high CD8+ cell density (OR, 2.69; 95% CI, 1.45-4.98; P = .002) was associated with good response to CRT, whereas high ITB (OR, 0.33; 95% CI, 0.14-0.80; P = .014) was associated with poor response. Multivariable Cox regression analysis for survival showed that high CD8+ cell density was associated with better recurrence-free survival (HR, 0.41; 95% CI, 0.24-0.72; P = .002) and overall survival (HR, 0.36; 95% CI, 0.17-0.74; P = .005), but significance values for ITB were marginal (P = .104 for recurrence-free survival and P = .163 for overall survival). The expression of EMT-related genes was not significantly different between patients with high and low ITB. CONCLUSION: ITB and CD8+ cell density in biopsy samples may serve as useful biomarkers to predict therapy response in patients with rectal cancer treated with neoadjuvant CRT.